Basic Linux commands

chmod [options] mode filename

Change a file's permissions.

passwd [name [password]]

Change the password or allow (for the system administrator) to change any password.

cd /directorypath

Change to directory.

chown [options] filename

Change who owns a file.

clear

Clear a command line screen/window for a fresh start.

cp [options] source destination

Copy files and directories.

mkdir [options] directory

Create a new directory.

ln [options] source [destination]

Create a shortcut.

touch filename

Create an empty file with the specified name.

rmdir [options] directory

Delete empty directories.

file [options] filename

Determine what type of data is within a file.

ps [options]

Display a snapshot of the currently running processes.

cat [filename]

Display file's contents to the standard output device (usually your monitor).

date [options]

Display or set the system date and time.

man [command]

Display the help information for the specified command.

tail [options] [filename]

Display the last n lines of a file (the default is 10).

pwd

Display the pathname for the current directory.

df [options]

Display used and available disk space.

who [options]

Display who is logged on.

top

Displays the resources being used on your system. Press q to exit.

ls [options]

List directory contents.

ssh [options] user@machine

Remotely log in to another Linux machine, over the network. Leave an ssh session by typing exit.

rm [options] directory

Remove (delete) file(s) and/or directories.

mv [options] source destination

Rename or move file(s) or directories.

locate filename

Search a copy of your filesystem for the specified filename.

grep [options] pattern [filesname]

Search files or output for a particular pattern.

find [pathname] [expression]

Search for files matching a provided pattern.

lpr [options]

Send a print job.

du [options]

Show how much space each file takes up.

kill [options] pid

Stop a process. If the process refuses to stop, use kill -9 pid.

tar [options] filename

Store and extract files from a tarfile (.tar) or tarball (.tar.gz or .tgz).

su [options] [user [arguments]]

Switch to another user account.

less [options] [filename]

View the contents of a file one page at a time.